This invention relates to seed planters. More particularly, this invention relates to seed planters having seed placement discs for placing the seeds into the soil at accurate intervals.
Seed planters are used in modern high-production farm operations to create a trench in the soil, deposit seeds into the bottom of the trench at accurate intervals, and then cover the trench. Seed planters are pulled behind a tractor and have a plurality of individual planter units arranged side-by-side so a plurality of parallel rows can be simultaneously planted. One type of seed planters is especially suited for planting relatively large seeds such as corn and soybeans.
A conventional corn and soybean seed planter is disclosed in Deckler, U.S. Pat. No. 3,999,690, issued Dec. 28, 1976, which is incorporated by reference. Each individual seed planter unit contains a seed hopper for holding a quantity of seeds, a seed meter for metering the seed, and a seed conveyor consisting of a drop chute through which the seeds pass from the meter to the soil. Each seed planter unit also contains a pair of trench forming discs in front of the drop chute and a soil packing wheel behind the drop chute. The drop chute is a hollow tube or rectangular duct having a length of about twenty-four inches. The seeds fall down through the drop chute by gravity. All seeds tumble and fall down the chute, but especially those with irregular, non-spherical shapes such as corn. The tumbling of the seeds creates some differences in the time it takes the seed to drop through the drop chute. These differences, in turn, cause the interval between planted seeds to vary somewhat. The variance is increased as the speed of the tractor pulling the planter increases. The spacing of seeds is extremely important because it has a major effect on crop yield. To keep the seed interval variance at an acceptable range, the maximum speed for planting corn with a conventional seed planter is about five miles per hour.
Accordingly, a demand exists for a seed planter that can plant the seeds at more accurate intervals so that the speed of the tractor can increase.
The general object of this invention is to provide an improved seed planter. A more particular object is to provide an improved seed planter that places seeds into an underlying trench at accurate intervals and that enables the seed planter to be pulled at greater speeds through the field.
I have invented an improved seed planter of the type that is pulled behind a tractor and that deposits seeds into an underlying trench in soil. The seed planter comprises: (a) a seed hopper for holding a quantity of seeds; (b) a seed meter for metering the flow of seeds to be planted which drops seed into a seed conveyor; (c) a trench former for forming an underlying trench in the soil; (d) a seed conveyor comprising a pair of rotating seed placement discs located behind the trench forming discs for conveying seeds from the seed meter into the trench at regular intervals, the seed placement discs having resilient annular rings attached to the perimeter of their inner facing sides, the rings being compressed together during a portion of their rotation below the seed meter and being spaced apart at a later portion of their rotation, such that a seed dropping from the seed meter is secured between the compressed rings and is then released to drop into the underlying trench as the rings separate; and (e) a trench closer located behind the seed placement discs for closing the trench and compacting the soil over the planted seeds.
The seed planter of this invention plants seeds at a very accurate interval and enables the seed planter to be pulled at greater speeds through the field.